BACKGROUND
[0001] An internet protocol (IP) source node, such as an IPv6 node, can steer a payload
packet through a specific path to a destination. For example, the source node may
define the path as an ordered list of segments and may encode the path in an IPv6
routing header.
SUMMARY
[0002] According to some implementations, a method may include receiving, by a node, an
internet protocol (IP) payload packet that has been encapsulated using an IPv6 transport
header. The IPv6 transport header may include a destination IP address of the node.
The IPv6 transport header may have been extended with a compressed routing header
(CRH). The CRH may include a list of segment identifiers (SIDs) that identify a set
of nodes that the IP payload packet is to traverse while being routed through a network.
The method may include determining, by the node and by referencing the list of SIDs
included in the CRH, a next segment for the IP payload packet. The method may include
updating, by the node and based on determining the next segment, the destination IP
address to a particular destination IP address of a next-hop node. The method may
include updating, by the node, a remaining segments value, that is included in the
CRH, that identifies a number of segments left in a route of the IP payload packet.
The method may include providing, by the node, the IP payload packet that includes
the CRH to the next-hop node to allow the next-hop node to route the IP payload packet
to another node in the network or to a destination device.
[0003] According to some implementations, a node may include one or more memories, and one
or more processors, to receive an internet protocol (IP) payload packet that that
has been encapsulated using an IPv6 transport header that has been extended with a
compressed routing header (CRH). The CRH may include a list of segment identifiers
(SIDs) that identify a set of nodes that the IP payload packet is to traverse while
being routed through a network. The list of SIDs may have variable lengths between
eight bits and sixty-four bits. The one or more processors may determine, by referencing
the list of SIDs, a next segment for the IP payload packet. The one or more processors
may update, based on determining the next segment, a destination IP address to a particular
destination IP address of a next-hop node. The one or more processors may update a
remaining segments value, that is included in the CRH, that identifies a number of
segments left in a route of the IP payload packet. The one or more processors may
provide the IP payload packet that includes the CRH to the next-hop node to allow
the next-hop node to route the IP payload packet to another node in the network or
to a destination device.
[0004] According to some implementations, a computer-readable medium may store one or more
instructions that, when executed by one or more processors of a node, cause the one
or more processors to receive an internet protocol (IP) payload packet that has been
encapsulated using a set of headers that include an IPv6 transport header. The IPv6
transport header may include a destination IP address of the node. The IPv6 transport
header may have been extended with a compressed routing header (CRH) that includes
a list of segment identifiers (SIDs) that identify a set of nodes that the IP payload
packet is to traverse while being routed through a network. The list of SIDs may have
variable lengths of: eight bits, sixteen bits, thirty-two bits, or sixty-four bits.
The one or more instructions may cause the one or more processors to determine, by
referencing the list of SIDs included in the CRH, a next segment for the IP payload
packet. The one or more instructions may cause the one or more processors to update
the destination IP address to a particular destination IP address of a next-hop node.
The one or more instructions may cause the one or more processors to update a remaining
segments value, that is included in the CRH, that identifies a number of segments
left in a route of the IP payload packet. The one or more instructions may cause the
one or more processors to provide the IP payload packet that includes the CRH to the
next-hop node to allow the next-hop node to route the IP payload packet to another
node in the network or to a destination device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005]
Figs. 1A-1H are diagrams of one or more example implementations described herein.
Fig. 2 is a diagram of an example compressed routing header (CRH).
Fig. 3 is a diagram of an example environment in which systems and/or methods described
herein may be implemented.
Fig. 4 is a diagram of example components of one or more devices of Fig. 3.
Figs. 5-7 are flow charts of an example process for routing a payload packet through
a network using a transport header that has been extended with a compressed routing
header (CRH).
DETAILED DESCRIPTION
[0006] The following detailed description of example implementations refers to the accompanying
drawings. The same reference numbers in different drawings may identify the same or
similar elements.
[0007] A network of nodes may be used to route packets. In many cases, the packets may be
routed through the network by taking a least cost path. For example, a packet may
have multiple possible paths through the network, and the nodes may use a routing
protocol (e.g., a Border Gateway Protocol (BGP), and/or the like) to select a least
cost path through the network route.
[0008] In some situations, segment routing may be used to allow the packets to be routed
using a path other than a least cost path. For example, a client using the network
to route packets may want the packets to travel through a particular firewall, to
avoid network congestion by taking a longer path through the network, and/or the like.
To route a packet through the network using segment routing, the packet may be encapsulated
using a Segment Routing Header that includes a list of IP addresses (or segment identifiers
with bit-lengths as long as IP addresses) that serve as required hops that the packet
is to take while being routed through the network. As an example, when a node in the
network receives a packet, the node may, instead of identifying a next hop in a least
cost path, process the list of IP addresses in the segment routing header to determine
whether a next hop is a required hop identified in the list.
[0009] However, segment routing is often an inefficient way to route packets through a network.
For example, many nodes used to route packets through the network have application-specific
integrated circuits (ASICs) that copy the entire list of IP addresses from buffer
memory to on-chip memory. If the list of IP addresses is long, the nodes may expend
significant processing resources performing copying operations and/or significant
memory resources storing the list.
[0010] Some implementations described herein provide a network of nodes that use a compressed
routing header (CRH) to route an encapsulated IP payload packet through a network
using a pre-defined path, where the CRH includes a list of segment identifiers (SIDs)
that have variable lengths between eight bits and sixty-four bits. For example, the
set of nodes may each be configured with particular segment translation tables that
define one or more segments of the pre-defined path. The segment translation table
may include strictly routed segments and/or loosely routed segments, as will be described
further herein. In this case, when a first edge node receives an IP payload packet,
the first edge node may encapsulate the IP payload packet using an IPv6 transport
header that has been extended to include the CRH. Additionally, the first edge node
may provide the IP payload packet to a first intermediary node in the network.
[0011] In this case, the first intermediary node may reference the list of SIDs included
in the CRH to select a SID. Additionally, the first intermediary node may reference
the segment translation table to identify a corresponding SID that is stored in association
with an IP address and/or interface of a next-hop node for the IP payload packet.
In this case, the first intermediary node may update a destination IP address (e.g.,
which may be included in the IPv6 transport header) to the IP address of the next-hop
node. Additionally, the first intermediary node may update a remaining segments value
of the CRH by decrementing the value by one.
[0012] Furthermore, the first intermediary node may provide the IP payload packet to the
next-hop node (e.g., another intermediary node, an endpoint node, etc.) to allow the
next-hop node to continue to route the IP payload packet. One or more additional nodes
in the network may use the list of SIDs to route the IP payload packet until the IP
payload packet is received by the endpoint node. When the endpoint node receives the
IP payload packet, the IP payload packet may have a remaining segments value of zero.
This may allow the endpoint node to process a payload header of the IP payload packet
(rather than the IPv6 transport header that is extended with the CRH) to identify
a final destination IP address of a final destination (e.g., a device outside of the
network) and to send the IP payload packet to the final destination.
[0013] In this way, the set of nodes are able to use the CRH to route the IP payload packet
through the network in a manner that uses a pre-defined path, without needing to include
IP addresses for each hop in the CRH. By using smaller values in the list of SIDs
(instead of a list of IP addresses), the set of nodes conserve resources (e.g., processing
resources, network resources, memory resources, and/or the like) relative to other
types of segment routing headers. For example, use of the CRH conserves processing
resources that the set of nodes would otherwise expend performing copy operations
on a longer more conventional segment routing header, conserves network resources
by reducing a total length of the IP payload packet that is being transmitted over
the network (relative to a conventional segment routing header), conserves memory
resources by reducing an amount of memory which may be needed to store the IP payload
packet (relative to a conventional segment routing header), and/or the like.
[0014] Furthermore, some implementations described herein allow the IP payload packet to
be routed through one or more strictly routed segments (defined further herein) using
one or more link-local IPv6 addresses. For example, for all segments except a final
segment, a node that receives the IP payload packet may update the destination IP
address to a link-local IPv6 address. This improves security by reducing chances of
the IP payload packet being routed off one of the strictly routed segments, as further
explained elsewhere herein. Additionally, by updating the destination IP address to
a global IP address on a final segment (rather than to a link-local IPv6 address),
the set of nodes further improves security by providing protection against link-local
address spoofing.
[0015] Figs. 1A-1H are diagrams of one or more example implementations 100 described herein.
For example, example implementation(s) 100 may include a first peer device (shown
as Peer Device 1), a second peer device (shown as Peer Device 2), and a set of nodes
that are part of a network, such as a first edge node (shown as Node A), a set of
intermediary nodes (shown as Node I1, Node 12, and Node 13), and a second edge node
(shown as Node B). As shown in Figs. 1A-1H, the set of nodes may be configured with
particular segment translation tables and may use the particular segment translation
tables to route, through the network, an internet protocol (IP) payload packet that
has been encapsulated using an IPv6 transport header that has been extended with a
compressed routing header (CRH).
[0016] As shown in Fig. 1A, and by reference number 102, the set of nodes may be configured
with a segment translation table. For example, the set of nodes may be configured
with a segment translation table that assists in routing network traffic via a specific
path. The segment translation table may be provided to the set of nodes via a network
controller, via a distributed routing protocol, and/or via another device or technique.
The segment translation table may include values that define one or more segments
of a path that an IP payload packet could take through the network. For example, the
segment translation table may include one or more strictly routed segments, one or
more loosely routed segments, and/or a combination of strictly and loosely routed
segments. A loosely routed segment may be defined as a path from a node to a terminal
interface, where the node and the terminal interface are connected via one or more
other nodes and/or links. A strictly routed segment may be defined as a path from
a node to a terminal interface, where there is exactly one link from the node to the
terminal interface.
[0017] In some implementations, a node may be configured with a segment translation table
that includes a set of strictly routed segments. The segment translation table may
include, for each strictly routed segment, a SID that is unique to the node, two IP
addresses (e.g., a global IP address, a link-local IPv6 address, etc.) that can be
used to identify an interface at which the strictly routed segment terminates (i.e.,
a terminal interface), and one link that connects the node to the terminal interface.
The SID may be represented by a value that is less expensive for nodes to copy than
an IP address (e.g., an eight-bit value, a sixteen-bit value, etc.). The interface
at which a strictly routed segment terminates is the global IP address (e.g., a globally-scoped
IP address, a unique local address (ULA), etc.) or the link-local IPv6 address. The
link-local IPv6 address may be used when sending IP payload packets to intermediary
nodes and the global IP address may be used when sending IP payload packets to an
edge node (e.g., an egress node).
[0018] As shown as an example, the set of network nodes may be configured with a segment
translation table that includes one or more strictly routed segments. In this example,
the first edge node (Node A) may be configured with a segment translation table with
two strictly routed segments. The first strictly routed segment may include a SID
of 129, a global IP address of 2001:db8::1 a link-local IPv6 address of fe80:0:0:1::2,
and an interface from the first edge node to the first intermediary node (shown as
A→I1). The second strictly routed segment may include a SID of 130, a global IP address
of 2001:db8::1, a link-local IPv6 address of fe80:0:0:2::2, and an interface from
the first edge node to the second intermediary node (shown as A→I2). In some cases,
an ingress node (e.g., the first edge node) may include a master list of segments
for the entire route of the IP payload packet (e.g., which are shown in Fig. 1A as
being part of segment translation tables for other nodes).
[0019] Additionally, or alternatively, a node may be configured with a segment translation
table that includes a set of loosely routed segments. The segment translation table
may include, for each loosely routed segment, a SID, an IP address that can be used
to identify a terminal interface, and one or more nodes and/or links that connect
the origin node and the terminal interface. The IP address is a global IP addresses
(e.g., a globally scoped address, a ULA, etc.). Furthermore, the segment translation
table that includes loosely routed segments may be configured to each of the set of
nodes.
[0020] In this way, the set of nodes may be configured with a segment translation table
that may be used to route IP payload packets through the network.
[0021] As shown in Fig. 1B, and by reference number 104, the first edge node may be configured
with route instructions. For example, the first edge node may be configured with route
instructions that specify a particular path that certain IP payload packets are to
take through the network, that identify one or more required hops that certain IP
payload packets are to take through the network, and/or the like. In this case, the
first edge node may be configured with route instructions that have been provided
by a network controller, by a device associated with a network administrator, by a
device of a client that has explicitly requested that certain IP payload packets be
subject to the route instructions, and/or the like. The route instructions may be
applicable to all IP payload packets, to a specific type of IP payload packets, to
IP payload packets with a particular source IP address and/or destination IP address,
and/or the like.
[0022] As an example, the route instructions may indicate that payload packets with a source
IP address of the first peer device and/or with a destination IP address of the second
peer device are to be routed from the first peer device (Peer Device 1) to the first
edge node (Node A), from the first edge node to the first intermediary node (Node
I1), from the first intermediary node to the third intermediary node (Node 13), from
the third intermediary node to the second edge node (Node B), and from the second
edge node to the second peer device (Peer Device 2).
[0023] As shown by reference number 106, the first peer device may provide an IP payload
packet to the first edge node. For example, the first peer device may encapsulate
an IP payload packet with a payload header (e.g., an IPv4 payload header, an IPv6
payload header, an ethernet payload header, etc.). The payload header may be an IPv4
payload header, an IPv6 payload header, an ethernet payload header, or the like. The
payload header may include a source IP address of the first peer device (shown as
192.179.1.11) and a destination IP address of the second peer device (shown as 192.179.2.10).
[0024] In this way, the first edge node is able to receive IP an IP payload packet from
the first peer device.
[0025] As shown in Fig. 1C, and by reference number 108, the first edge node may encapsulate
the IP payload packet using an IPv6 transport header that has been extended using
a compressed routing header (CRH). For example, the first edge node may reference
the segment translation table and/or the route instructions to determine that the
IP payload packet is to be encapsulated using an IPv6 transport header that has been
extended with a CRH. As an example, the route instructions may indicate that IP payload
packets with a particular source IP address or destination IP address are to be encapsulated
with an IPv6 transport header that is extended with a CRH.
[0026] The CRH may include a list of SIDs that define the path for the IP payload packet,
a total segments value, a remaining segments value, a compression value, a next header
value, a header extension length, a routing type, and a reserved value. The list of
SIDs may include a list of node-specific values that correspond to a list of SIDs
included in the segment translation table. The total segments value may identify a
maximum number of segments which may be needed for the IP payload packet to reach
a final-hop node (e.g., the second edge device). The remaining segments value may
identify a number of remaining segments between an origin node (e.g., the node that
receives the IP payload packet) and the second edge node. A description of the remaining
values of the CRH may be found below in relation to Fig. 2.
[0027] In some implementations, before determining which values to include in the CRH, the
first edge node may update the source IP address and the destination IP address included
in the IPv6 transport header. For example, the first edge node may update the source
IP address with the global IP address of the first edge node and may update the destination
IP address with the link-local IPv6 address of the next-hop node (which may be found
in the segment translation table).
[0028] In some implementations, the first edge node may select which values to include in
the CRH. For example, the first edge node may select, as values for the list of SIDs,
the values that are identified in the segment translation table. Additionally, the
first edge node may determine a total segments value based on a number of entries
in the list of SIDs. One or more additional values in the CRH may be selected or generated
in a manner described elsewhere herein.
[0029] In some implementations, the first edge node may encapsulate the IP payload packet
using the IPv6 transport header that has been extended with the CRH. For example,
the first edge node may encapsulate the IP payload packet such that the IPv6 transport
header is an outer-most header of the IP payload packet. Between the IP payload packet
and the IPv6 transport header may be a set of extension headers (e.g., a hop-by-hop
extension header, a routing extension header, a destination header, etc.) which are
not part of the processes described herein.
[0030] As shown by reference number 110, the first edge node may provide the IP payload
packet that has been encapsulated to the first intermediary node. In this way, the
first edge node is able to encapsulate the IP payload packet using the IPv6 transport
header that has been extended with the CRH and is able to use values included in the
CRH to route the IP payload packet to the next-hop in the network.
[0031] As shown in Fig. 1D, the first intermediary node may perform one or more header pre-processing
checks and/or one or more security checks on the IP payload packet. For example, and
as shown by reference number 112, the first intermediary node may determine whether
the destination IP address that is included in the IPv6 transport header matches an
IP address of the first intermediary node. This is because the set of nodes are configured
to process, update, and/or modify the CRH only if the destination IP address that
is included in the IPv6 transport header matches an IP address of a node. In this
example, the first intermediary node may determine that the destination IP address
matches the IP address of the first intermediary node (e.g., the IPv6 transport header
is shown as having a destination IP address of fe80:0:0:1::2, which is the link-local
IPv6 address of the first intermediary node).
[0032] As shown by reference number 114, the first intermediary node may determine a number
of remaining segments in a path of the IP payload packet. For example, the first intermediary
node may process the remaining segments value of the CRH to determine the number of
remaining segments in the path. If the remaining segments value is greater than zero,
then the first intermediary node may continue processing the CRH. If the remaining
segments value is zero, then the first intermediary node may stop processing the CRH
and process a next header of the IP payload packet (e.g., one of the extension headers,
the payload header, etc.). In practice, the remaining segments value will be zero
only when a final node in the network is receiving the IP payload packet. This provides
the final node with a way to identify when the IP payload packet has reached a final
hop in the network and may cause the final node to forgo processing of the CRH and
to route the IP payload packet to a device outside of the network, as will be described
further herein.
[0033] As shown by reference number 116, the first intermediary node may perform one or
more security checks. For example, the first intermediary node may determine whether
the source IP address included in the IPv6 transport header is a link-local IPv6 address,
may determine whether the source IP address or destination IP address included in
the IPv6 transport header is a multicast address, may determine whether a hop limit
has been exceeded, may determine whether the IP payload packet is malformed, and/or
the like. To provide an example, assume an IP payload packet is encapsulated using
an IPv6 transport header that has been extended with a CRH that is sixteen bytes long
and that includes a total segments value of sixty-four (where each segment is one
byte). In this example, sixty-four one-byte segments would not fit into a sixteen
byte CRH, which means the payload packet has been malformed. In this case, the first
intermediary node would identify that the payload packet is malformed and would discard
the payload packet.
[0034] In this way, the first intermediary node performs one or more header pre-processing
checks and/or one or more security checks on the IP payload packet (e.g., on one or
more headers of the IP payload packet).
[0035] As shown in Fig. IE, and by reference number 118, the first intermediary node may
determine a next segment for the IP payload packet. For example, the first intermediary
node may determine an index i for the next segment by subtracting a remaining segments
value from a total segments value. In the example shown, the total segments value
indicates that there are two total segments and the remaining segments value indicates
that there are two segments left. By subtracting the remaining segments value from
the total segments value, the first intermediary node may determine that the index
i has a value of zero.
[0036] Additionally, the first intermediary node may identify a SID number at index position
i in the list of SIDs. In the example shown, the SID value at segment[0] is 129. Furthermore,
this allows the first intermediary node to determine the next segment by searching
the segment translation table for a corresponding SID that may be stored in association
with a global IP address of a next-hop node, a link-local IPv6 address of a next-hop
node, and a link identifier of a link to the next-hop node.
[0037] As shown by reference number 120, the first intermediary node may update the destination
IP address of the IP payload packet and the remaining segments value. For example,
the first intermediary node may translate the destination IP address with a global
IP address or a link-local IPv6 address of the next-hop node. In this case, the first
intermediary node may translate the destination IP address with the global IP address
if the remaining segments value is one (or another value that indicates that a next
segment is a final segment) or may replace the destination IP address with the link-local
IPv6 address if the remaining segments value is greater than one (or another value
that indicates that the next segment is not the final segment). In some cases, the
first intermediary node may translate an eight-bit, sixteen-bit, thirty-two-bit, or
sixty-four-bit segment identifier, to a one hundred and twenty-eight-bit IPv6 address.
[0038] By updating the destination IP address included in the IPv6 transport header with
the global IP address at a penultimate node, the penultimate node ensures that the
IP payload packet will never have a link-local address when routed to a final destination
(e.g., the second peer device). This protects from various classes of attacks in which
an off-link attacker may attempt to assume on-link status by using a link-local address.
By replacing the destination IP address included in the IPv6 transport header with
the link-local IPv6 address, a node that performs the update protects against certain
classes of mis-programming. For example, between a time that the IP payload packet
was sent and a time that the IP payload packet arrived at the first intermediary node,
the first intermediary node may have received instructions to update the segment translation
table. In this case, the first intermediary node might, based on the updated segment
translation table, mistakenly send the IP payload packet to a neighboring node that
is not part of the strictly routed path of the IP payload packet. However, because
the destination IP address will be updated to a link-link-local IPv6 address, the
neighboring node that was not supposed to receive the IP payload packet would drop
the IP payload packet. This is because nodes that are not part of the strictly routed
path may be configured to drop IP payload packets that have a link-local IPv6 source
or destination IP address.
[0039] In some implementations, the first intermediary node may update the remaining segments
value. For example, the first intermediary node may decrement the remaining segments
value by one. In the example shown, the first intermediary node may decrement the
remaining segments value from a value of two to a value of one.
[0040] In this way, the first intermediary node is able to use the CRH to determine the
next segment for the IP payload packet and is able to update one or more values of
the IP payload packet that allow subsequent nodes to continue to route the IP payload
packet.
[0041] As shown in Fig. IF, and by reference number 122, the first intermediary node may
provide the IP payload packet that has been encapsulated to the third intermediary
node. The IPv6 transport header of the IP payload packet may include a source IP address
of the first endpoint node and a destination IP address that is a link-local IPv6
address of the third intermediary node.
[0042] As shown by reference number 124, the third intermediary node may determine whether
the destination IP address included in the IPv6 transport header matches an IP address
of the third intermediary node, in a manner described elsewhere herein. As shown by
reference number 126, the third intermediary node may determine a number of remaining
segments in the path of the IP payload packet, in a manner described elsewhere herein.
In the example shown, the third intermediary node may determine that there is one
remaining segment, which may cause the third intermediary node to continue processing
the CRH. As shown by reference number 128, the third intermediary node may perform
one or more security checks, in a manner described elsewhere herein.
[0043] In this way, the third intermediary node is able to perform the one or more header
pre-processing checks and/or the one or more security checks on the IP payload packet.
[0044] As shown in Fig. 1G, and by reference number 130, the third intermediary node may
determine a next segment. For example, the third intermediary node may determine the
next segment in a manner described elsewhere herein.
[0045] In the example shown, the total segments value indicates that there are two total
segments and the remaining segments value indicates that there is one remaining segment.
By subtracting the remaining segments value from the total segments value, the third
intermediary node may determine that the index i has a value of one. Additionally,
the third intermediary node may process the list of SIDs to identify that a SID at
index position 1 has a value of 129. This may allow the third intermediary node to
determine the next segment by searching the segment translation table for a corresponding
SID value of 129, which is stored in association with a global IP address of 2001:db8::3,
a link-local IPv6 address of fe80:0:0:b::2, and a link identifier of a link from the
third intermediary node to the second edge node.
[0046] As shown by reference number 132, the third intermediary node may update the destination
IP address of the IP payload packet and the remaining segments value included in the
CRH. For example, the third intermediary node may replace the destination IP address
included in the IPv6 transport header with a global IP address or a link-local IPv6
address of a next-hop node. In this case, the third intermediary node may determine
that the remaining segments value is one, and, based on determining that the remaining
segments value is one, may update the destination IP address included in the IPv6
transport header with the global IP address of the next-hop node. In the example shown,
the third intermediary node may update the destination IP address from a value of
fe80:0:0:3::2 to a value of 2001:db8::b.
[0047] Additionally, the third intermediary node may decrement the remaining segments value
by one. In the example shown, the third intermediary node may decrement the remaining
segments value from a value of one to a value of zero.
[0048] In this way, the third intermediary node is able to determine the next segment for
the IP payload packet and is able to update one or more values of the IP payload packet
to allow subsequent nodes to continue to route the IP payload packet.
[0049] As shown in Fig. 1H, and by reference number 134, the third intermediary node may
provide the IP payload packet that has been encapsulated to the second edge node (Node
B). The IP payload packet may include a source IP address of the first edge node (2001:db8::a)
and a destination IP address of the second edge node (2001:db8::b). In some implementations,
the second edge node may perform one or more header pre-processing checks, in a manner
described elsewhere herein.
[0050] As shown by reference number 136, the second edge node may determine a next-hop for
the IP payload packet based on the number of remaining segments. For example, the
second edge node may process the CRH to determine that the remaining segments value
is equal to zero.
[0051] In some implementations, because the remaining segments value is zero, the second
edge node may forgo additional processing of the CRH and may process one more other
headers of the IP payload packet (e.g., the payload header, etc.). In the example
shown, the payload header may include a destination IP address for the second peer
device (192.172.1.10), which may allow the second edge device to route the IP payload
packet to the second peer device.
[0052] In some implementations, the second edge node may determine a next-hop by referencing
a segment translation table. While not shown, the second edge node may be configured
with a segment translation table that has the destination IP address of the second
peer device stored as part of the translation table (e.g., in place of the global
IP address, and with a null value for a link-link-local IPv6 address), and may reference
the segment translation table to identify the destination IP address of the second
peer device.
[0053] In this way, the set of nodes are able to use the CRH to route the IP payload packet
through the network in a manner that uses a strictly defined path, without needing
to include IP addresses for each hop in the strictly defined path in the segment list.
This conserves resources (e.g., processing resources, network resources, memory resources,
and/or the like) relative to other types of segment routing headers that would expend
a significant amount of resources performing copy operations on a longer more conventional
segment routing header.
[0054] As indicated above, Figs. 1A-1H are provided by way of example. Other examples may
differ from what is described with regard to Figs. 1A-1H. For example, there may be
additional devices and/or networks, fewer devices and/or networks, different devices
and/or networks, or differently arranged devices and/or networks than those shown
in Figs. 1A-1H. Furthermore, two or more devices shown in Figs. 1A-1H may be implemented
within a single device, or a single device shown in Figs. 1A-1H may be implemented
as multiple and/or distributed devices. Additionally, or alternatively, a set of devices
(e.g., one or more devices) of example implementation(s) 100 may perform one or more
functions described as being performed by another set of devices of example implementation(s)
100.
[0055] Fig. 2 is a diagram of an example compressed routing header (CRH) 200. As shown in
Fig. 2, CRH 200 may include a next header field, a header extension length field,
a routing type field, a remaining segments field (shown as Segments Left), a total
segments field (shown as Num Segments), a reserved field, a compression field, and
a list of segment identifiers (SIDs) field. The next header field may include an eight-bit
selector value that identifies a type of header immediately following an internet
protocol (IP) header (e.g., an IPv6 header). The header extension length field may
include an eight-bit unsigned integer value that identifies a length of a hop-by-hop
options header in eight-octet units, but that excludes the first eight octets.
[0056] The routing type field may include an eight-bit identifier value for a particular
routing header variant, as may be defined by the internet assigned numbers authority
(IANA). The remaining segments field may include a value that identifies a number
of remaining segments between an origin node (e.g., a node that receives an IP payload
packet) and a final-hop node (e.g., a node that is part of a final segment in a path).
The total segments field may include a value that identifies a maximum number of segments
which may be needed for an IP payload packet to reach the final-hop node. This value
may be defined by a number of entries in the list of SIDs. The reserved field may
include a value set to zero by a sender node and ignored by a receiver node.
[0057] The compression field may include a two-bit value that may be checked to determine
whether an IP payload packet is malformed. For example, the compression field may
include a value that a node may process to determine a minimum CRH length, which may
allow the node to determine whether the IP payload packet is malformed. The minimum
CRH length is measured in eight-octet units that exclude the first eight octets. The
compression field may include a value of zero, one, two, or three. The value of zero
may correspond to an eight-bit encoding, the value of one may correspond to a sixteen-bit
encoding, the value of two may correspond to a thirty-two-bit encoding, and the value
of three may correspond to a sixty-four-bit encoding. Additionally, if the compression
value is set to a value of two or a value of three, the list of SIDs begins on a thirty-two-bit
boundary. In those cases, the reserved field may be extended. In all cases, the CRH
ends on a sixty-four-bit boundary. Therefore, the CRH may be padded with zeroes.
[0058] As an example, to compute the minimum CRH length, a node may provide a compression
value and a total number of segments value as input to an algorithm that computes
the minimum CRH length. To provide example pseudocode, the node might execute the
following: If (compression value == 0), set a value x equal to a total segments value
minus two, set the compression value equal to x divided by eight, and, if x divided
by eight has a remainder, increment the compression value by one. If (compression
value == 1), set x equal to a total segments value minus one, set the compression
value equal to x divided by four, and, if x divided by four has a remainder, increment
the compression value by one. If (compression value == 2), set x equal to the total
number of segments, set the compression value equal to x divided by two, and, if x
divided by two has a remainder, increment the compression value by one. If (compression
value == 3), set the compression value equal to the total segments value.
[0059] The list of SIDs field may include a set of SID values that represent segments in
the list of segments. In some implementations, such as when the list of segments includes
loosely routed segments, each SID may include a unique value. In some implementations,
such as when the list of segments includes strictly routed segments, each SID may
be unique to a node, such that the same SID value could be used on multiple nodes.
[0060] As indicated above, Fig. 2 is provided by way of example. Other examples may differ
from what is described with regard to Fig. 2. For example, there may be additional
fields and/or values, fewer fields and/or values, different fields and/or values,
or differently arranged fields and/or values than those shown in Fig. 2.
[0061] Fig. 3 is a diagram of an example environment 300 in which systems and/or methods
described herein may be implemented. As shown in Fig. 3, environment 300 may include
one or more peer devices 310, a group of nodes 320 (shown as node 320-1 through node
320-N), and a network 330. Devices of environment 300 may interconnect via wired connections,
wireless connections, or a combination of wired and wireless connections.
[0062] Peer device 310 includes one or more devices capable of receiving and/or providing
network traffic. For example, peer device 310 may include a traffic transfer device,
such as a router, a gateway, a switch, a firewall, a hub, a bridge, a reverse proxy,
a server (e.g., a proxy server, a server executing a virtual machine, etc.), a security
device, an intrusion detection device, a load balancer, or a similar type of device.
In some implementations, peer device 310 may include an endpoint device that is a
source or a destination for network traffic. For example, peer device 310 may include
a computer or a similar type of device. Peer device 310 may receive network traffic
from and/or may provide network traffic (e.g., payload packets) to other peer devices
310 via network 330 (e.g., by routing payload packets using node(s) 320 as an intermediary).
In some implementations, peer device 310 may include an edge device that is located
at an edge of one or more networks. For example, peer device 310 receive network traffic
from and/or may provide network traffic (e.g., payload packets) to devices external
to network 330.
[0063] Node 320 includes one or more devices capable of receiving, processing, storing,
routing, and/or providing traffic (e.g., a payload packet, a file, etc.) in a manner
described herein. For example, node 320 may include a router, such as a label switching
router (LSR), a label edge router (LER), an ingress router, an egress router, a provider
router (e.g., a provider edge router, a provider core router, etc.), a virtual router,
and/or the like. Additionally, or alternatively, node 320 may include a gateway, a
switch, a firewall, a hub, a bridge, a reverse proxy, a server (e.g., a proxy server,
a cloud server, a data center server, etc.), a load balancer, and/or a similar device.
[0064] In some implementations, node 320 may be a physical device implemented within a housing,
such as a chassis. In some implementations, node 320 may be a virtual device implemented
by one or more computer devices of a cloud computing environment or a data center.
[0065] In some implementations, node 320 may be configured with one or more segment translation
tables. In some implementations, node 320 may receive a payload packet from peer device
310. In some implementations, node 320 may encapsulate the payload packet using a
compressed routing header (CRH) and may route the IP payload packet to another node
320, using one or more techniques described elsewhere herein. In some implementations,
node 320 may be an edge node in network 330. In some implementations, node 320 may
be an intermediary node in network 330 (i.e., a node between two or more edge nodes).
[0066] Network 330 includes one or more wired and/or wireless networks. For example, network
330 may include a cellular network (e.g., a fifth generation (5G) network, a fourth
generation (4G) network, such as a long-term evolution (LTE) network, a third generation
(3G) network, a code division multiple access (CDMA) network, a public land mobile
network (PLMN), a local area network (LAN), a wide area network (WAN), a metropolitan
area network (MAN), a telephone network (e.g., the Public Switched Telephone Network
(PSTN)), a private network, an ad hoc network, an intranet, the Internet, a fiber
optic-based network, a cloud computing network, or the like, and/or a combination
of these or other types of networks.
[0067] The number and arrangement of devices and networks shown in Fig. 3 are provided as
one or more examples. In practice, there may be additional devices and/or networks,
fewer devices and/or networks, different devices and/or networks, or differently arranged
devices and/or networks than those shown in Fig. 3. Furthermore, two or more devices
shown in Fig. 3 may be implemented within a single device, or a single device shown
in Fig. 3 may be implemented as multiple, distributed devices. Additionally, or alternatively,
a set of devices (e.g., one or more devices) of environment 300 may perform one or
more functions described as being performed by another set of devices of environment
300.
[0068] Fig. 4 is a diagram of example components of a device 400. Device 400 may correspond
to peer device 310 and/or node 320. In some implementations, peer device 310 and/or
node 320 may include one or more devices 400 and/or one or more components of device
400. As shown in Fig. 4, device 400 may include one or more input components 405-1
through 405-B (B ≥ 1) (hereinafter referred to collectively as input components 405,
and individually as input component 405), a switching component 410, one or more output
components 415-1 through 415-C (C ≥ 1) (hereinafter referred to collectively as output
components 415, and individually as output component 415), and a controller 420.
[0069] Input component 405 may be points of attachment for physical links and may be points
of entry for incoming traffic, such as payload packets. Input component 405 may process
incoming traffic, such as by performing data link layer encapsulation or decapsulation.
In some implementations, input component 405 may send and/or receive payload packets.
In some implementations, input component 405 may include an input line card that includes
one or more payload packet processing components (e.g., in the form of integrated
circuits), such as one or more interface cards (IFCs), payload packet forwarding components,
line card controller components, input ports, processors, memories, and/or input queues.
In some implementations, device 400 may include one or more input components 405.
[0070] Switching component 410 may interconnect input components 405 with output components
415. In some implementations, switching component 410 may be implemented via one or
more crossbars, via busses, and/or with shared memories. The shared memories may act
as temporary buffers to store payload packets from input components 405 before the
payload packets are eventually scheduled for delivery to output components 415. In
some implementations, switching component 410 may enable input components 405, output
components 415, and/or controller 420 to communicate.
[0071] Output component 415 may store payload packets and may schedule payload packets for
transmission on output physical links. Output component 415 may support data link
layer encapsulation or decapsulation, and/or a variety of higher-level protocols.
In some implementations, output component 415 may send payload packets and/or receive
payload packets. In some implementations, output component 415 may include an output
line card that includes one or more payload packet processing components (e.g., in
the form of integrated circuits), such as one or more IFCs, payload packet forwarding
components, line card controller components, output ports, processors, memories, and/or
output queues. In some implementations, device 400 may include one or more output
components 415. In some implementations, input component 405 and output component
415 may be implemented by the same set of components (e.g., and input/output component
may be a combination of input component 405 and output component 415).
[0072] Controller 420 includes a processor, such as a central processing unit (CPU), a graphics
processing unit (GPU), an accelerated processing unit (APU), a microprocessor, a microcontroller,
a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific
integrated circuit (ASIC), and/or another type of processor or processing component.
The processor is implemented in hardware, firmware, or a combination of software and
hardware. In some implementations, controller 420 may include one or more processors
that can be programmed to perform a function.
[0073] In some implementations, controller 420 may include a random access memory (RAM),
a read only memory (ROM), and/or another type of dynamic or static storage device
(e.g., a flash memory, a magnetic memory, an optical memory, etc.) that stores information
and/or instructions for use by controller 420.
[0074] In some implementations, controller 420 may communicate with other devices, networks,
and/or systems connected to device 400 to exchange information regarding network topology.
Controller 420 may create translation tables based on the network topology information,
create forwarding tables based on the translation tables, and forward the forwarding
tables to input components 405 and/or output components 415. Input components 405
and/or output components 415 may use the forwarding tables to perform route lookups
for incoming and/or outgoing payload packets. In some cases, controller 420 may create
a session table based on information determined while initializing a link fault detection
(e.g., BFD) session, and may forward the session table to input components 405 and/or
output components 415.
[0075] Controller 420 may perform one or more processes described herein. Controller 420
may perform these processes in response to executing software instructions on a computer-readable
medium. A computer-readable medium may be a non-transitory medium, such as a memory
device for example storage discs and solid state devices. A memory device includes
memory space within a single physical storage device or memory space spread across
multiple physical storage devices. In other examples, a computer-readable medium may
be a transitory medium such as a carrier signal or a transmission medium.
[0076] Software instructions may be read into a memory and/or storage component associated
with controller 420 from another computer-readable medium or from another device via
a communication interface. When executed, software instructions stored in a memory
and/or storage component associated with controller 420 may cause controller 420 to
perform one or more processes described herein. Additionally, or alternatively, hardwired
circuitry may be used in place of or in combination with software instructions to
perform one or more processes described herein. Thus, implementations described herein
are not limited to any specific combination of hardware circuitry and software.
[0077] The number and arrangement of components shown in Fig. 4 are provided as an example.
In practice, device 400 may include additional components, fewer components, different
components, or differently arranged components than those shown in Fig. 4. Additionally,
or alternatively, a set of components (e.g., one or more components) of device 400
may perform one or more functions described as being performed by another set of components
of device 400.
[0078] Fig. 5 is a flow chart of an example process 500 for routing a payload packet through
a network using a transport header that has been extended with a compressed routing
header (CRH). In some implementations, one or more process blocks of Fig. 5 may be
performed by a node (e.g., node 320). In some implementations, one or more process
blocks of Fig. 5 may be performed by another device or a group of devices separate
from or including the node, such as a peer device (e.g., peer device 310).
[0079] As shown in Fig. 5, process 500 may include receiving an internet protocol (IP) payload
packet that has been encapsulated using an IPv6 transport header, wherein the IPv6
transport header includes a destination IP address of the node, wherein the IPv6 transport
header has been extended with a compressed routing header (CRH) of variable length,
and wherein the CRH includes a list of segment identifiers (SIDs) that identify a
set of nodes that the IP payload packet is to traverse while being routed through
a network (block 510). For example, the node (e.g., using input component 405, switching
component 410, controller 420, and/or the like) may receive an internet protocol (IP)
payload packet that has been encapsulated using an IPv6 transport header, as described
above. In some implementations, the IPv6 transport header may include a destination
IP address of the node. In some implementations, the IPv6 transport header may have
been extended with a compressed routing header (CRH) of variable length. In some implementations,
the CRH may include a list of segment identifiers (SIDs) that identify a set of nodes
that the IP payload packet is to traverse while being routed through a network.
[0080] As further shown in Fig. 5, process 500 may include determining, by referencing the
list of SIDs included in the CRH, a next segment for the IP payload packet (block
520). For example, the node (e.g., using controller 420) may determine, by referencing
the list of SIDs included in the CRH, a next segment for the IP payload packet, as
described above.
[0081] As further shown in Fig. 5, process 500 may include updating, based on determining
the next segment, the destination IP address to a particular destination IP address
of a next-hop node (block 530). For example, the node (e.g., using controller 420)
may update, based on determining the next segment, the destination IP address to a
particular destination IP address of a next-hop node, as described above.
[0082] As further shown in Fig. 5, process 500 may include updating a remaining segments
value, that is included in the CRH, that identifies a number of segments left in a
route of the IP payload packet (block 540). For example, the node (e.g., using controller
420) may update a remaining segments value, that is included in the CRH, that identifies
a number of segments left in a route of the IP payload packet, as described above.
[0083] As further shown in Fig. 5, process 500 may include providing the IP payload packet
that includes the CRH to the next-hop node to allow the next-hop node to route the
IP payload packet to another node in the network or to a destination device (block
550). For example, the node (e.g., using switching component 410, output component
415, controller 420, and/or the like) may provide the IP payload packet that includes
the CRH to the next-hop node to allow the next-hop node to route the IP payload packet
to another node in the network or to a destination device, as described above.
[0084] Process 500 may include additional implementations, such as any single implementation
or any combination of implementations described below and/or in connection with one
or more other processes described elsewhere herein.
[0085] In some implementations, list of SIDs may have variable lengths of: eight bits, sixteen
bits, thirty-two bits, or sixty-four bits. In some implementations, a set of segments
in the route of the IP payload packet may include at least one of: a strictly routed
segment, or a loosely routed segment. In some implementations, a final segment in
the route of the IP payload packet may be a strictly routed segment. In some implementations,
the node may configure a segment translation table that associates two or more of:
a set of SIDs that correspond to the list of SIDs, a set of global IP addresses, a
set of link-local IPv6 addresses, or a set of interface mappings.
[0086] In some implementations, when determining the next segment for the IP payload packet,
the node may identify a SID, of the list of SIDs included in the CRH, that is associated
with the node, and may determine the next segment by using the SID to reference a
segment translation table that maps the SID to a global IP address of the next-hop
node and to a link-local IPv6 address that identifies an interface of the next-hop
node, and, when updating the destination IP address, the node may update the destination
IP address with the global IP address or the link-local IPv6 address based on whether
the next segment is a final segment.
[0087] In some implementations, when updating the destination IP address, the node may update,
based on the next segment being a final segment of the route, the destination IP address
to a global IP address, where the destination IP address is updated to the global
IP address and not to a link-local IPv6 address based on the next segment being the
final segment of the route.
[0088] Although Fig. 5 shows example blocks of process 500, in some implementations, process
500 may include additional blocks, fewer blocks, different blocks, or differently
arranged blocks than those depicted in Fig. 5. Additionally, or alternatively, two
or more of the blocks of process 500 may be performed in parallel.
[0089] Fig. 6 is a flow chart of an example process 600 for routing a payload packet through
a network using a transport header that has been extended with a compressed routing
header (CRH). In some implementations, one or more process blocks of Fig. 6 may be
performed by a node (e.g., node 320). In some implementations, one or more process
blocks of Fig. 6 may be performed by another device or a group of devices separate
from or including the node, such as a peer device (e.g., peer device 310).
[0090] As shown in Fig. 6, process 600 may include receiving an internet protocol (IP) payload
packet that has been encapsulated using an IPv6 transport header that has been extended
with a compressed routing header (CRH), wherein the CRH includes a list of segment
identifiers (SIDs) that identify a set of nodes that the IP payload packet is to traverse
while being routed through a network, and wherein the list of SIDs have variable lengths
between eight bits and sixty-four bits (block 610). For example, the node (e.g., using
input component 405, switching component 410, controller 420, and/or the like) may
receive an internet protocol (IP) payload packet that includes a set of headers, as
described above.
[0091] As further shown in Fig. 6, process 600 may include determine, by referencing the
list of SIDs, a next segment for the IP payload packet (block 620). For example, the
node (e.g., using controller 420) may determine, by referencing the list of SIDs,
a next segment for the IP payload packet, as described above.
[0092] As further shown in Fig. 6, process 600 may include updating a destination IP address
to a particular destination IP address of a next-hop node (block 630). For example,
the node (e.g., using controller 420) may update a destination IP address to a particular
destination IP address of a next-hop node, as described above.
[0093] As further shown in Fig. 6, process 600 may include updating a remaining segments
value, that is included in the CRH, that identifies a number of segments left in a
route of the IP payload packet (block 640). For example, the node (e.g., using controller
420) may update a remaining segments value, that is included in the CRH, that identifies
a number of segments left in a route of the IP payload packet, as described above.
[0094] As further shown in Fig. 6, process 600 may include providing the IP payload packet
that includes the CRH to the next-hop node to allow the next-hop node to route the
IP payload packet to another node in the network or to a destination device (block
650). For example, the node (e.g., using switching component 410, output component
415, controller 420, and/or the like) may provide the IP payload packet that includes
the CRH to the next-hop node to allow the next-hop node to route the IP payload packet
to another node in the network or to a destination device, as described above.
[0095] Process 600 may include additional implementations, such as any single implementation
or any combination of implementations described below and/or in connection with one
or more other processes described elsewhere herein.
[0096] In some implementations, a set of segments in the route of the IP payload packet
may include strictly routed segments. In some implementations, a final segment in
the route of the IP payload packet may be a strictly routed segment. In some implementations,
the node may configure, before receiving the IP payload packet, a segment translation
table that associates two or more of: a set of SIDs that correspond to the list of
SIDs, a set of global IP addresses, a set of link-local IPv6 addresses, or a set of
interface mappings.
[0097] In some implementations, when determining the next segment for the IP payload packet,
the node may identify a SID, of the list of SIDs included in the CRH, that is associated
with the node, and may determine the next segment by using the SID to reference a
segment translation table that maps the SID to a global IP address of the next-hop
node, and a link-local IPv6 address that identifies an interface of the next-hop node.
The global IP address or the link-local IPv6 address may be used as the destination
IP address of the IP payload packet. In some implementations, when updating the destination
IP address, the node may update the destination IP address with the global IP address
of the node or the link-local IPv6 address of the next-hop node based on whether the
next segment is a final segment.
[0098] In some implementations, when updating the destination IP address, the node may update,
based on the next segment being a final segment of the route, the destination IP address
to the particular destination IP address, where the particular destination IP address
is a global IP address, and where the final segment is a strictly routed segment.
In some implementations, the node may determine, before determining the next segment,
whether the remaining segments value included in the CRH is a non-zero value and may
determine whether to continue processing the CRH or to process another header of the
set of headers based on whether the remaining segments value is the non-zero value.
[0099] Although Fig. 6 shows example blocks of process 600, in some implementations, process
600 may include additional blocks, fewer blocks, different blocks, or differently
arranged blocks than those depicted in Fig. 6. Additionally, or alternatively, two
or more of the blocks of process 600 may be performed in parallel.
[0100] Fig. 7 is a flow chart of an example process 700 for routing a payload packet through
a network using a transport header that has been extended with a compressed routing
header (CRH). In some implementations, one or more process blocks of Fig. 7 may be
performed by a node (e.g., node 320). In some implementations, one or more process
blocks of Fig. 7 may be performed by another device or a group of devices separate
from or including the node, such as a peer device (e.g., peer device 310).
[0101] As shown in Fig. 7, process 700 may include receive an internet protocol (IP) payload
packet that has been encapsulated using a set of headers that include an IPv6 transport
header, wherein the IPv6 transport header includes a destination IP address of the
node, wherein the IPv6 transport header has been extended with a compressed routing
header (CRH) that includes a list of segment identifiers (SIDs) that identify a set
of nodes that the IP payload packet is to traverse while being routed through a network,
and wherein the list of SIDs have variable lengths of eight bits, sixteen bits, thirty-two
bits, and sixty-four bits (block 710). For example, the node (e.g., using input component
405, switching component 410, controller 420, and/or the like) may receive an IP payload
packet that has been encapsulated using a set of headers that include a CRH and a
destination header, as described above. In some implementations, the CRH may include
a list of segment identifiers (SIDs) that identify a set of nodes that the IP payload
packet is to traverse while being routed through a network, and the list of SIDs have
variable lengths of eight bits, sixteen bits, thirty-two bits, or sixty-four bits.
[0102] As further shown in Fig. 7, process 700 may include determining, by referencing the
list of SIDs included in the CRH, a next segment for the IP payload packet (block
720). For example, the node (e.g., using controller 420) may determine, by referencing
the list of SIDs included in the CRH, a next segment for the IP payload packet, as
described above.
[0103] As further shown in Fig. 7, process 700 may include updating the destination IP address
to a particular destination IP address of a next-hop node (block 730). For example,
the node (e.g., using controller 420) may update the destination IP address to a particular
destination IP address of a next-hop node, as described above.
[0104] As further shown in Fig. 7, process 700 may include updating a remaining segments
value, that is included in the CRH, that identifies a number of segments left in a
route of the IP payload packet (block 740). For example, the node (e.g., using controller
420) may update a remaining segments value, that is included in the CRH, that identifies
a number of segments left in a route of the IP payload packet, as described above.
[0105] As further shown in Fig. 7, process 700 may include providing the IP payload packet
that includes the CRH to the next-hop node to allow the next-hop node to route the
IP payload packet to another node in the network or to a destination device (block
750). For example, the node (e.g., using controller 420) may provide the IP payload
packet that includes the CRH to the next-hop node to allow the next-hop node to route
the IP payload packet to another node in the network or to a destination device, as
described above.
[0106] Process 700 may include additional implementations, such as any single implementation
or any combination of implementations described below and/or in connection with one
or more other processes described elsewhere herein.
[0107] In some implementations, a set of segments in the route of the IP payload packet
may include at least one strictly routed segment. In some implementations, a final
segment in the route of the IP payload packet may be a strictly routed segment. In
some implementations, the node may configure, before receiving the IP payload packet,
a segment translation table that associates two or more of: a set of SIDs that correspond
to the list of SIDs, a set of global IP addresses, a set of link-local IPv6 addresses,
or a set of interface mappings.
[0108] In some implementations, when determining the next segment for the IP payload packet,
the node may identify a SID, of the list of SIDs included in the CRH, that is associated
with the node, and may determine the next segment by using the SID to reference a
segment translation table that maps the SID to a global IP address of the next-hop
node, and a link-local IPv6 address that identifies an interface of the next-hop node.
The global IP address or the link-local IPv6 address may be used as the destination
IP address of the IP payload packet. In some implementations, when updating the destination
IP address, the node may update the destination IP address with the global IP address
of the node or the link-local IPv6 address of the next-hop node based on whether the
next segment is a final segment.
[0109] In some implementations, when updating the destination IP address, the node may update,
based on the next segment being a final segment of the route, the destination IP address
to a global IP address, where the destination IP address is updated to the global
IP address and not to a link-local IPv6 address based on the next segment being the
final segment of the route.
[0110] Although Fig. 7 shows example blocks of process 700, in some implementations, process
700 may include additional blocks, fewer blocks, different blocks, or differently
arranged blocks than those depicted in Fig. 7. Additionally, or alternatively, two
or more of the blocks of process 700 may be performed in parallel.
[0111] The foregoing disclosure provides illustration and description but is not intended
to be exhaustive or to limit the implementations to the precise forms disclosed. Modifications
and variations may be made in light of the above disclosure or may be acquired from
practice of the implementations.
[0112] As used herein, the term network traffic or content may include a set of payload
packets. A payload packet may refer to a communication structure for communicating
information, such as a protocol data unit (PDU), a network payload packet, a datagram,
a segment, a message, a block, a cell, a frame, a subframe, a slot, a symbol, a portion
of any of the above, and/or another type of formatted or unformatted unit of data
capable of being transmitted via a network. An internet protocol (IP) payload packet,
as used herein, may refer to an IPv4 payload packet, an IPv6 payload packet, an ethernet
payload packet, and/or the like.
[0113] As used herein, the term "component" is intended to be broadly construed as hardware,
firmware, and/or a combination of hardware and software.
[0114] Some implementations are described herein in connection with thresholds. As used
herein, satisfying a threshold may, depending on the context, refer to a value being
greater than the threshold, more than the threshold, higher than the threshold, greater
than or equal to the threshold, less than the threshold, fewer than the threshold,
lower than the threshold, less than or equal to the threshold, equal to the threshold,
or the like.
[0115] It will be apparent that systems and/or methods described herein may be implemented
in different forms of hardware, firmware, or a combination of hardware and software.
The actual specialized control hardware or software code used to implement these systems
and/or methods is not limiting of the implementations. Thus, the operation and behavior
of the systems and/or methods are described herein without reference to specific software
code-it being understood that software and hardware can be designed to implement the
systems and/or methods based on the description herein.
[0116] Even though particular combinations of features are recited in the claims and/or
disclosed in the specification, these combinations are not intended to limit the disclosure
of various implementations. In fact, many of these features may be combined in ways
not specifically recited in the claims and/or disclosed in the specification. Although
each dependent claim listed below may directly depend on only one claim, the disclosure
of various implementations includes each dependent claim in combination with every
other claim in the claim set.
[0117] No element, act, or instruction used herein should be construed as critical or essential
unless explicitly described as such. Also, as used herein, the articles "a" and "an"
are intended to include one or more items and may be used interchangeably with "one
or more." Furthermore, as used herein, the term "set" is intended to include one or
more items (e.g., related items, unrelated items, a combination of related and unrelated
items, etc.), and may be used interchangeably with "one or more." Where only one item
is intended, the phrase "only one" or similar language is used. Also, as used herein,
the terms "has," "have," "having," or the like are intended to be open-ended terms.
Further, the phrase "based on" is intended to mean "based, at least in part, on" unless
explicitly stated otherwise.
[0118] Thus, from one perspective, there has now been described a node that receives an
internet protocol (IP) payload packet that includes an IPv6 transport header that
has been extended with a compressed routing header (CRH). The CRH includes a list
of segment identifiers (SIDs) that identify nodes that the IP payload packet is to
traverse. The node determines, by referencing the list of SIDs, a next segment for
the IP payload packet. The node updates a destination IP address that is included
in the IPv6 transport header to a particular destination IP address of a next-hop
node. The node updates a remaining segments value, included in the CRH, that identifies
a number of segments left in a route of the IP payload packet. The node provides the
IP payload packet to the next-hop node to allow the next-hop node to route the IP
payload packet to another node in the network or to a destination device.
[0119] Further examples of feature combinations taught by the present disclosure are set
out in the following numbered clauses:
- 1. A method, comprising:
receiving, by a node, an internet protocol (IP) payload packet that has been encapsulated
using an IPv6 transport header,
wherein the IPv6 transport header includes a destination IP address of the node,
wherein the IPv6 transport header has been extended with a compressed routing header
(CRH) of variable length, and
wherein the CRH includes a list of segment identifiers (SIDs) that identify a set
of nodes that the IP payload packet is to traverse while being routed through a network;
determining, by the node and by referencing the list of SIDs included in the CRH,
a next segment for the IP payload packet;
updating, by the node and based on determining the next segment, the destination IP
address to a particular destination IP address of a next-hop node;
updating, by the node, a remaining segments value, that is included in the CRH, that
identifies a number of segments left in a route of the IP payload packet; and
providing, by the node, the IP payload packet that includes the CRH to the next-hop
node to allow the next-hop node to route the IP payload packet to another node in
the network or to a destination device.
- 2. The method of clause 1, wherein the list of SIDs have variable lengths of:
eight bits,
sixteen bits,
thirty-two bits, or
sixty-four bits.
- 3. The method of clause 1 or 2, wherein a set of segments in the route of the IP payload
packet include at least one of:
a strictly routed segment, or
a loosely routed segment.
- 4. The method of any of clauses 1 to 3, wherein a final segment in the route of the
IP payload packet is a strictly routed segment.
- 5. The method of any of clause 1 to 4, further comprising:
configuring the node with a segment translation table that associates two or more
of:
a set of SIDs that correspond to the list of SIDs,
a set of global IP addresses,
a set of link-local IPv6 addresses, or
a set of interface mappings.
- 6. The method of any of clauses 1 to 5, wherein determining the next segment for the
IP payload packet comprises:
identifying a SID, of the list of SIDs included in the CRH, that is associated with
the node, and
determine the next segment by using the SID to reference a segment translation table
that maps the SID to:
a global IP address of the next-hop node, and
a link-local IPv6 address that identifies an interface of the next-hop node; and
wherein updating the destination IP address comprises:
updating the destination IP address with the global IP address of the node or the
link-local IPv6 address of the next-hop node based on whether the next segment is
a final segment.
- 7. The method of any of clauses 1 to 5, wherein updating the destination IP address
comprises:
updating, based on the next segment being a final segment of the route, the destination
IP address to a global IP address,
wherein the destination IP address is updated to the global IP address and not to
a link-local IPv6 address based on the next segment being the final segment of the
route.
- 8. A node, comprising:
one or more memories; and
one or more processors, to:
receive an internet protocol (IP) payload packet that has been encapsulated using
an IPv6 transport header that has been extended with a compressed routing header (CRH),
wherein the CRH includes a list of segment identifiers (SIDs) that identify a set
of nodes that the IP payload packet is to traverse while being routed through a network,
and
wherein the list of SIDs have variable lengths between eight bits and sixty-four bits;
determine, by referencing the list of SIDs, a next segment for the IP payload packet;
update a destination IP address to a particular destination IP address of a next-hop
node;
update a remaining segments value, that is included in the CRH, that identifies a
number of segments left in a route of the IP payload packet; and
provide the IP payload packet that includes the CRH to the next-hop node to allow
the next-hop node to route the IP payload packet to another node in the network or
to a destination device.
- 9. The node of clause 8, wherein a set of segments in the route of the IP payload
packet include strictly routed segments.
- 10. The node of clause 8 or 9, wherein a final segment in the route of the IP payload
packet is a strictly routed segment.
- 11. The node of any of clauses 8 to 10, wherein the one or more processors are further
to:
configure, before receiving the IP payload packet, the node with a segment translation
table that associates two or more of:
a set of SIDs that correspond to the list of SIDs,
a set of global IP addresses,
a set of link-local IPv6 addresses, or
a set of interface mappings.
- 12. The node of any of clauses 8 to 11, wherein the one or more processors, when determining
the next segment for the IP payload packet, are to:
identify a SID, of the list of SIDs included in the CRH, that is associated with the
node, and
determine the next segment by using the SID to reference a segment translation table
that maps the SID to:
a global IP address of the next-hop node, and
a link-local IPv6 address that identifies an interface of the next-hop node; and
wherein the one or more processors, when updating the destination IP address, are
to:
update the destination IP address with the global IP address of the node or the link-local
IPv6 address of the next-hop node based on whether the next segment is a final segment.
- 13. The node of any of clauses 8 to 12, wherein the one or more processors, when updating
the destination IP address, are to:
update, based on the next segment being a final segment of the route, the destination
IP address to the particular destination IP address,
wherein the particular destination IP address is a global IP address, and
wherein the final segment is a strictly routed segment.
- 14. The node of any of clauses 8 to 13, wherein the one or more processors are further
to:
determine, before determining the next segment, whether the remaining segments value
included in the CRH is a non-zero value, and
determine whether to continue processing the CRH or to process another header of the
set of headers based on whether the remaining segments value is the non-zero value.
- 15. A computer-readable medium carrying instructions that, when executed by one or
more processors of a node, cause the one or more processors to:
receive an internet protocol (IP) payload packet that has been encapsulated using
a set of headers that include an IPv6 transport header,
wherein the IPv6 transport header includes a destination IP address of the node,
wherein the IPv6 transport header has been extended with a compressed routing header
(CRH) that includes a list of segment identifiers (SIDs) that identify a set of nodes
that the IP payload packet is to traverse while being routed through a network, and
wherein the list of SIDs have variable lengths of:
eight bits,
sixteen bits,
thirty-two bits, or
sixty-four bits;
determine, by referencing the list of SIDs included in the CRH, a next segment for
the IP payload packet;
update the destination IP address to a particular destination IP address of a next-hop
node;
update a remaining segments value, that is included in the CRH, that identifies a
number of segments left in a route of the IP payload packet; and
provide the IP payload packet that includes the CRH to the next-hop node to allow
the next-hop node to route the IP payload packet to another node in the network or
to a destination device.
- 16. The computer-readable medium of clause 15, wherein a set of segments in the route
of the IP payload packet include at least one strictly routed segment.
- 17. The computer-readable medium of clause 15 or 16, wherein a final segment in the
route of the IP payload packet is a strictly routed segment.
- 18. The computer-readable medium of any of clause 15 to 17, wherein the instructions,
when executed by the one or more processors, further cause the one or more processors
to:
configure, before receiving the IP payload packet, the node with a segment translation
table that associates two or more of:
a set of SIDs that correspond to the list of SIDs,
a set of global IP addresses,
a set of link-local IPv6 addresses, or
a set of interface mappings.
- 19. The computer-readable medium of any of clause 15 to 18, wherein the instructions,
that cause the one or more processors to determine the next segment for the IP payload
packet, cause the one or more processors to:
identify a SID, of the list of SIDs included in the CRH, that is associated with the
node, and
determine the next segment by using the SID to reference a segment translation table
that maps the SID to:
a global IP address of the next-hop node, and
a link-local IPv6 address that identifies an interface of the next-hop node; and
wherein the instructions, that cause the one or more processors to update the destination
IP address, cause the one or more processors to:
update the destination IP address with the global IP address of the node or the link-local
IPv6 address of the next-hop node based on whether the next segment is a final segment.
- 20. The computer-readable medium of any of clause 15 to 18, wherein the instructions,
that cause the one or more processors to update the destination IP address, cause
the one or more processors to:
update, based on the next segment being a final segment of the route, the destination
IP address to a global IP address,
wherein the destination IP address is updated to the global IP address and not to
a link-local IPv6 address based on the next segment being the final segment of the
route.